Semiconductor integrated circuit (IC) technology has experienced rapid progress including the continued minimization of feature sizes and the maximization of packing density. The minimization of feature size relies on improvement in photolithography and its ability to print smaller features or critical dimensions (CD). For example, extreme ultraviolet (EUV) lithography is introduced for patterning smaller features in advanced technology nodes. Photomasks are used in the photolithography patterning and are fabricated using electro-beam (e-beam) writing. However, the second electron scattering reduces contrast and resolution. The degradation of the e-beam writing by the second electron scattering effect is even worse for EUV photomask fabrication.
Therefore, a photomask structure, method making the same and method using the same are needed to address the above issues.